I had a bad week. I was sent a spreadsheet recording all the flies that Peter Chandler had found during our Stirling fly week frenzy, and I discovered that, had I been more diligent, I might have added Bolitophilidae, Brachystomatidae, Ditomyiidae, Micropezidae, Pseudopomyzidae, Diadocidiidae, Pallopteridae, Therevidae, Platystomatidae and Platypezidae to my list of families. Of course, comparison is odious, and Peter, being an elder statesman in the world of flies, knows what he is doing, but all the same, I felt as if I had failed, or at least not done quite as well as I might. Having only found one new family in the last two months I was reduced to identifying hoverflies.
But just beyond my back door, creeping out of the forest floor as summer sidles off to become autumn, are suddenly a flurry of fungi, new arrivals poking their heads up to be greeted by adoring slugs, beetles and, I was hoping, flies. There are two techniques you can use. One is to take them by surprise, sweeping over the top and around the fungus honeypot and then pootering anything interesting out of the net. More satisfying is to get down to humus-level and wait for things to arrive.
At first there was nothing, everything having been scared off as I lumbered up and hunkered down, flat on my belly in a nose-to-gills stance driven by my short-sightedness, pooter at the ready. Hopefully there would be no passers-by to wonder if I was a corpse or to ask what I was doing. The rich black smell of rotting fungus flesh was quite strong and the ground wasn’t quite as dry, nor as comfortable as I had imagined. Partly filtered by the swaying tree tops, the grey sky began emptying itself. The uneven contours of my chosen fungus became familiar, a yellow mucous covered slab sinking earthward. My alert eye picked up tiny movements, but only of bugs, beetles and spiders. Then, darting out of a slug hole, dizzyingly circumnavigating the cap and disappearing again after some unexpected twirls and fancy footwork was a frenetic fly. Next time I was ready with my pooter and, eventually, potted it.
Nothing much to look at you might think, another dull brown fly. But do the wings not seem a little broader than strictly necessary or usual for such a little fly? And one of the veins at the wing tip arrives there after splitting off perversely from its proper direction. Even stranger, the hind feet are like a nightmare vision of what women’s footwear could be like with a properly sadistic designer.
What were these ladies (I only caught ladies) doing with these pumped up, awkward-fitting and faintly repulsive tarsi, like grey liver lobes? Might it help them from skidding around on the slippery surface of a mushroom? I doubt it. Perhaps in attracting a mate – tastes differ of course. Any explanation has to cope with the fact that in different genera it is either the males or the females that have these flat-feet (hence Platypezidae – flat footed flies). At least it’s an appropriate family to echo my own feeling of being a little slow on the fly front. Must plod more.